The European Patent Application Publication No. 0097734 discloses a truck weighing apparatus having a platform made of usual concrete, the platform being supported by force measuring elements in a pit made of usual concrete and forming a base the top of which being provided with a circumferential frame the top surface of which flushing with the top surface of the platform. The platform and the frame are made at the operational site by using a lost, self-supporting shuttering or form for the platform. The form consists of a plurality of form elements made of steel sheets which are fixedly secured to each other by screws or rivets. Base members for supporting the force measuring elements may be casted separately or simultaneously with the platform. The production and assembly of the self-supporting form using steel sheets are time-consuming and expensive in respect of the material used, since each steel sheet has to be formed individually and secured to another steel sheet. The concrete used as restricted in its tensile strength, such that heavy reinforcements and a considerable thickness is necessary when the apparatus is used as a truck weighing apparatus. The base member in the pit must have an exactly defined form and high-quality concrete must be used therefore. Also, considerable care is necessary when casting the frame of the base member. There is a relatively wide gap between the platform and the frame permitting penetration of dirt and humidity into the pit. Moreover, specific bumpers made of metal are provided to restrict a lateral movement of the platform within the base member. The force measuring elements arranged between the platform and the bottom of the base member can be accessed from the pit only necessitating a separate entrance thereto.
The European Patent Application Publication No. 0108164 discloses a platform weighing apparatus using a platform made of steel provided with openings for inserting the force measuring elements.
The U.S. Pat. No. 4,549,622 discloses a platform weighing apparatus the platform of which is made of concrete and is supported on shear beam type load cells arranged at each corner of the platform. Support means for the platform and the load cells are of the self-restoring type absorbing any lateral forces.
At least a dozen years ago another type of concrete has become known which is called "polymeric concrete". This material uses synthetic resins as a binder for filler materials, as sand. Polymeric concrete has a far better tensile strength than usual concrete and an excellent resistancy against chemical substances. Up to now this material has been used in replacement of usual concrete for plates and tubes and for support bases of tooling machines. However, up to now polymeric concrete was not used in connection with weighting systems, apparently because of the quite different characteristics in respect of thermal expansion and costs.